Beta Acid's first chronological appearance is in Zero Mission. It floods the Zebesian Command Center after it is destroyed by a Self-Destruct System, replacing the lava that was previously found in the room.
This substance is not present in the ruined Zebesian Command Center in Super Metroid, which could suggest that it dried up or was drained from the room. However, Super Metroid does feature the functionally-identical scalding-hot lava in both Tourian bases; since this lava is referred to as acid in other languages, it could therefore potentially be intended as the same substance as Beta Acid despite the different color.
Beta Acid is also present aboard the Biologic Space Laboratories research station. It is found exclusively in several corridors in the Tourian-like area of Sector 1 (SRX), including the room before Neo-Ridley's chamber.
- Metroid Fusion: The Official Nintendo Player's Guide refers to the substance as "dangerous liquid" and "dangerous water". The former name was also used to refer to the unknown liquid that blocked off many caverns on SR388 in Metroid II: Return of Samus.
- This substance, possessing corrosive properties and a green color, may be yet another reference to the Alien film franchise, as the Aliens in the franchise have acidic green blood.
- The appearance of the liquid bears a striking similarity to waste found in Metroid Prime 3: Corruption. However, the waste is not harmful.
|Hazardous||Acid (Beta/Fake) • Acid Rain • Afloraltite • Dark Water • Fire • Fuel Gel • Lava (Fake/Scalding-hot) • Phazon • Purple liquid|
|Gases||Dark vapor • Industrial-grade pesticide • Meta-viprium gas • Nohadin gas • Noxious gasses • Poison gas • Talvania Gas|
|Destructible|| Barnacle-like material • Bendezium • Brinstone • Cordite • Denzium • Frigidite • Glass • Grobnite • Ice • Maldium • Meltable Metal • Metroid webs • Radion • Sandstone • Talloric Alloy • Vegetation • Zebetite |
Kelbium and Zafrite
|Phazon||Red • Crystal • Black Crystal • Mass • Ore • Elite Nutrient Mix • Strain Vertigo • Phazite (Red) • Concentrated|
|Crystals||Ammolite/Witherite Shards • Black Phazon • Crystallized Fuel Gel • Crystals • Dark Sentinel • Lift • Liftvine • Light • Minerals • Phazon • Red magma • Sentinel|
|Ore||Urthic • Phazon|
|Miscellaneous|| Invisible platform • Jovian steel • Liquid Resource • Liquid solution • Sand |
Vaccine "Metroid" • Waste • Water • Yellow goo • Yellow liquid